Fastening devices are known in many variants. The spacer has the purpose in particular of decoupling the contact surface for a component to be attached by the fastening device, which may be a sensor housing for example, from the possibly curved shape of the support panel, which is oriented for example according to aesthetic requirements of an auto body.
To provide for a particularly economical operation of motor vehicles, efforts are made to build them in a light-weight manner. This also has effects on the body, in that the latter is manufactured of the thinnest sheet metal possible. The problem can then occur that the body is plastically deformed in the area of the bushing due to the tightening torque of the clamping element to achieve the prescribed fastening force for the structural element, and is partially drawn into the bushing.
As a result of this unintended indentation, with surface coated support panels, for example painted auto bodies, the surface coating on the external side opposite the mounting side can become cracked in an unwanted manner, which later constitutes a potential rust location at this position.